1. Field of the Invention
The present invention relates to a circular saw, and more particularly to a circular saw which has a table, a saw unit having a saw blade and slidably mounted on the table, and a slide stopper mechanism for fixing the saw unit in position in a sliding direction relative to the table.
2. Description of the Prior Art
A conventional circular saw is disclosed in Japanese Utility Model Publication No. 4-44321 and includes a stopper mechanism which has an operation knob adapted to be rotated by an operator. The operation knob is disposed on a rear side of a saw unit which is the side opposite to a front side where the operator is positioned for operating the saw unit. With this arrangement, in order to operate the operation knob, the operator must reach out his hand to the rear side of the saw unit and grope for the operation knob to grasp the same. Therefore, the conventional circular saw has a problem in its operability. In particular, since the operation knob is positioned on the rear side of the saw unit, the operator feels difficulty in getting a view of the operation knob. In addition, in some cases, the knob is covered by a dust absorbing bag which is normally mounted on the rear portion of the saw unit, so that the knob is difficult to be operated in this respect.
Further, in case of a circular saw which has a saw unit slidably movable relative to a turntable and rotatable with the turntable, the position of an operation knob is changed for each rotational operation of the turntable. Therefore, the operator must grope for the operation knob in a further unreliable manner. Otherwise, the operator must move from the position on the front side of the saw unit to a different position for visually recognize the position of the knob before he operates the knob. The conventional circular saw has a problem in its operability also in this respect.
In another aspect, with a conventional circular saw having a turntable rotatable with a saw unit, a rotation stopper mechanism is normally provided for fixing the rotational position of the turntable. Japanese Laid-Open Utility Model Publication No. 54-39692 discloses a circular saw having a rotation lock mechanism. The rotation lock mechanism includes a lock pin mounted on a front side of the turntable and includes lock holes formed in a base on which the turntable is rotatably supported. The lock pin is biased by a spring in a direction toward the base for insertion into any one of the lock holes. The lock pin is removed from the corresponding lock hole when an operator pulls the lock pin forwardly toward himself, so that the turntable is brought to be free to rotate. When the operator releases the lock pin with the turntable positioned in a desired position, the lock pin is brought to be inserted into the corresponding lock hole by the biasing force of the spring, so that the turntable is fixed in position in the rotational direction.
However, the operation for releasing the lock pin is rather difficult for the operator since he must pull the lock pin toward himself and since the pulling operation must be made against the biasing force of the spring. The conventional circular saw has a problem in its operability also in this respect.